How to prevent engine from starting and put it in neutral

You can put a Prius into neutral when it's in ON mode (rather than READY), and it can't start the engine then.

Press the POWER button twice without foot on the brake pedal to get to ON. Then you can shift to N.

 

What’s the miles on it?

 

If, the prius you're asking about is a Plugin like the one shown in your profile, and everything else in the car is working normally, the default READY mode at startup is EV mode. Double check that all accessories are off while in ON mode, especially the HAVC system.

If you want to experiment a bit you can also remove the spark plugs, than see what is shown when you push the start button a few times both with foot off the brake pedal and foot on the brake pedal.

Might also want to learn how to remove any coolant that might be in the cylinders, while spark plugs removed.

 

This is a moment for Westheimer's observation, a coupla months in the laboratory can save you a coupla hours in the library, only for this question of course nowhere near that kind of time is needed.

The owners' manual already flat-out tells you what happens when you push the button once with no brake, twice with no brake, and once with brake, and that information is worth memorizing so you know it in your sleep without having to experiment.

Once with no brake is ACC, and the radio works, and a few other things like the power outlets.

Twice with no brake is ON, and all the ACC stuff works plus the instruments, and you can shift between P and N.

Once with the brake is READY, and you risk the engine starting.

 

So sorry you didn't like my alternative suggestions for a owner worried about hydro\locking if his engine starts.

 

sorry, I thought that knowing it's still there would be a good enough clue that maybe someone else would be able to find it too. Keepin my fingers crossed that it will stay that way (available) at least for a little while longer . I did have to re read the license agreement -before.